Ness of Clousta - The Brigs

Site of Special Scientific Interest · 60.3097, -1.4491

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Also within

Shetland County

Condition (NatureScot)

Favourable (1)
UnitFeatureConditionArea (ha)Assessed
F1 Old Red Sandstone Igneous Favourable — 2012-12-17

Habitats

Fast flowing river and stream

Geology & landscape

Rock Type: Conglomerate, Sandstone

Landscape processes: Fluvial, Volcanic / Igneous

Description

Ness of Clousta - The Brigs Ness of Clousta is approximately 4.5 km north-west of Aith in west Mainland Shetland. This site exposes the middle Old Red Sandstone Clousta conglomerate and contemporaneous volcanic tuff rings. The outcrops indicate that the conglomerate was deposited by a braided stream in an alluvial fan setting. Of particular interest is the presence of tuff rings which interfinger with the conglomerates. The Muckle Head and Muckle Billerin tuffs are basic in composition and represent portions of phreato-magmatic pyroclastic cones. In the case of Muckle Billerin an associated basic lava flow is present. The Brigs tuff is acidic in composition and contains angular clasts of feldspar porphyry probably originating through explosive disruption of an already largely consolidated lava dome. These outcrops show the way the braided rivers were displaced by, and then slowly buried by the tuffs in a remarkable demonstration of sediment/volcanic relationships.

Plant communities

A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream

Potamogeton natans community

Schoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa

A14 — Fast flowing river and stream

Myriophyllum alterniflorum community

Isolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina

A17 — Chalk river and stream, Fast flowing river and stream

Ranunculus penicillatus ssp. pseudofluitans community

Berula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans

A18 — Fast flowing river and stream

Ranunculus fluitans community

Fontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea